Washington — Hillary Rodham Clinton would send prominent emissaries to world capitals the day after being elected president. John McCain would close the Guantánamo detention facility and renounce the use of torture. Barack Obama would speak to all foreign leaders, even America's worst enemies.

With global views of the United States seemingly stuck at historic lows, improving America's image abroad has emerged as a prominent issue of the 2008 presidential campaign. In debates and speeches, candidates acknowledge to varying degrees that everything from the prospects for diplomatic initiatives to America's economic well-being in the global economy hinges in part on how the world views the US.

And they are offering ideas, like those cited above, for how the image slide can be reversed.

But changing America's world image will take more than campaign rhetoric, experts say, especially in the post-9/11 era. Although they note that much of the blame for a deteriorated image is placed at the feet of President Bush, they say it won't work for the next president to seek a return to where the US was in 2000. Rather, they say, the next US leader should try to discern the kind of leadership the world is craving for the 21st century.

"The image challenge is much more about substance than symbols; but changing some of what the world perceived as the more egregious policies of George Bush will be necessary but far from sufficient," says Bruce Jentleson, a professor of public policy at Duke University in Durham, N.C., and a member of the State Department policy planning staff during the Clinton presidency. "The next president has to realize the world has changed, and there's no going back to square one."

The sharp decline in America's image abroad is acknowledged by the Bush administration, which has launched various public-diplomacy campaigns to try to reverse it. At one point, Mr. Bush named one of his closest advisers, Karen Hughes, to take on the task of polishing America's brand around the world. Despite those efforts, a majority in many countries that once had a positive opinion of the US now view it negatively.

Reversing the low stature may be helped along by the arrival of a fresh face in the White House, but what it will really take is a change in unpopular policies, analysts say – from the war in Iraq to the more restrictive criteria for granting US visas. But some unpopular policies, among them some of those resulting from 9/11, are likely to remain unchanged no matter who is president.

"The rise of anti-American sentiment is linked to specific policies. You can't just say it's a matter of rhetoric," says Nikolas Gvosdev, editor of the National Interest, a Washington-based foreign-policy review. "But that means changing it will be easier said than done."

In fact, there is likely to be a certain "continuity" to US foreign policy, Mr. Gvosdev predicts, especially on 9/11-driven security measures.

"People have bought into a narrative that all this negativity is the result of one man, or maybe two men in the White House, the president and vice president," he says. "But to suggest that on Jan. 20, 2009, everything will change to the world's liking doesn't take into account how the world has changed."

Candidates have already indicated the various means they would employ – in some cases reminiscent of the unilateral actions much of the world bemoaned in Bush – to assure America's security.

Take the Democrats' Mr. Obama, for example, who speaks frequently of the consequences of America's poor image abroad. The senator often asserts that the world will start to see the US differently the day he is elected because he is African-American. But he has also said that he would be ready to send US troops into Pakistan if he had credible intelligence that pointed to an effective strike against the Al Qaeda leadership – even if the Pakistani regime opposed the action.

That has led some commentators to compare Obama's position to the "Bush doctrine" outlined by the president in 2002. But others say Obama is talking about a specific case and not a policy. "The Democrats still do have a bit of a perception problem on national security. I'd say that's what [Obama] was addressing there," says Mr. Jentleson of Duke. "It was a specific case, not a statement of a presidential doctrine."

More long term, he says his organization's surveys show that the people of many countries will warm to the US if they see it as resuming leadership of a rules-based international system – one many believe the US violated with the war in Iraq.